I have a HW100kt, it dont need a soft alloy after market cylinder that you cant take off without the cylinder dumping all its air, the rifle is perfectly balanced straight from the factory and i feel safer with a made by the factory stainless steel cylinder that can be taken off the rifle without loosing any air, makes it easier to service the rifle, as for selling the rifle, i will only buy an all original rifle with matching serial numbers, i wont touch any tampered with rifle, especially if it has some home made air cylinder on it, even if it has been tested, i dont find a HW100kt a heavy r